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Re: [PATCH] kill prom_printf

To: "Maciej W. Rozycki" <macro@ds2.pg.gda.pl>
Subject: Re: [PATCH] kill prom_printf
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Tue, 17 Jun 2003 16:38:39 +0200 (MEST)
Cc: Ladislav Michl <ladis@linux-mips.org>, Juan Quintela <quintela@trasno.org>, Linux/MIPS Development <linux-mips@linux-mips.org>
In-reply-to: <Pine.GSO.3.96.1030617155734.22214I-100000@delta.ds2.pg.gda.pl>
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
On Tue, 17 Jun 2003, Maciej W. Rozycki wrote:
> On Tue, 17 Jun 2003, Ladislav Michl wrote:
> > >  There is also that minor implementation problem -- how to pass varargs
> > > from printk() to ROM's printf()?  At least the firmware of the DECstation
> > > implements a full-featured printf() as in the C library.
> > 
> > you are implementing early console not printf (sorry again for confusion),
> > so there is no need to pass varargs anywhere. btw, early_printk() as known
> > from other archs is supposed to die in future. printk() should be used
> > everywhere.
> 
>  Hmm, calling the firmware for each character separately will certainly be
> terribly slow, though it may be negligible as normally few messages will
> be output this way.  And since the call to prom_printf() is so cheap for
> the DECstation, I'm going to retain the function for real low-level
> debugging, whether otherwise used or not. 

kernel/printk.c doesn't call the low-level output routine for each character
separately, but passes complete strings of characters.

Gr{oetje,eeting}s,

                                                Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                                            -- Linus Torvalds


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